diff --git a/gateway/platforms/email.py b/gateway/platforms/email.py
index 2a38d699e..9d1244135 100644
--- a/gateway/platforms/email.py
+++ b/gateway/platforms/email.py
@@ -28,6 +28,7 @@ from email.header import decode_header
 from email.mime.multipart import MIMEMultipart
 from email.mime.text import MIMEText
 from email.mime.base import MIMEBase
+from email.utils import formatdate
 from email import encoders
 from pathlib import Path
 from typing import Any, Dict, List, Optional
@@ -504,6 +505,7 @@ class EmailAdapter(BasePlatformAdapter):
             msg["In-Reply-To"] = original_msg_id
             msg["References"] = original_msg_id
 
+        msg["Date"] = formatdate(localtime=True)
         msg_id = f"<hermes-{uuid.uuid4().hex[:12]}@{self._address.split('@')[1]}>"
         msg["Message-ID"] = msg_id
 
@@ -586,6 +588,7 @@ class EmailAdapter(BasePlatformAdapter):
             msg["In-Reply-To"] = original_msg_id
             msg["References"] = original_msg_id
 
+        msg["Date"] = formatdate(localtime=True)
         msg_id = f"<hermes-{uuid.uuid4().hex[:12]}@{self._address.split('@')[1]}>"
         msg["Message-ID"] = msg_id
 
diff --git a/tests/gateway/test_email.py b/tests/gateway/test_email.py
index c8eecf38e..7c1d0d48e 100644
--- a/tests/gateway/test_email.py
+++ b/tests/gateway/test_email.py
@@ -488,6 +488,7 @@ class TestThreadContext(unittest.TestCase):
             self.assertEqual(send_call["Subject"], "Re: Project question")
             self.assertEqual(send_call["In-Reply-To"], "<original@test.com>")
             self.assertEqual(send_call["References"], "<original@test.com>")
+            self.assertIn("Date", send_call)
 
     def test_reply_does_not_double_re(self):
         """If subject already has Re:, don't add another."""
@@ -519,6 +520,7 @@ class TestThreadContext(unittest.TestCase):
 
             send_call = mock_server.send_message.call_args[0][0]
             self.assertEqual(send_call["Subject"], "Re: Hermes Agent")
+            self.assertIn("Date", send_call)
 
 
 class TestSendMethods(unittest.TestCase):
@@ -889,6 +891,11 @@ class TestSendEmailStandalone(unittest.TestCase):
             self.assertEqual(result["platform"], "email")
             _, kwargs = mock_server.starttls.call_args
             self.assertIsInstance(kwargs["context"], ssl.SSLContext)
+            send_call = mock_server.send_message.call_args[0][0]
+            self.assertEqual(send_call["Subject"], "Hermes Agent")
+            self.assertIn("Date", send_call)
+            self.assertEqual(send_call["To"], "user@test.com")
+            self.assertEqual(send_call["From"], "hermes@test.com")
 
     @patch.dict(os.environ, {
         "EMAIL_ADDRESS": "hermes@test.com",
diff --git a/tools/send_message_tool.py b/tools/send_message_tool.py
index c36e54e02..a2321c2e5 100644
--- a/tools/send_message_tool.py
+++ b/tools/send_message_tool.py
@@ -1075,6 +1075,7 @@ async def _send_email(extra, chat_id, message):
     """Send via SMTP (one-shot, no persistent connection needed)."""
     import smtplib
     from email.mime.text import MIMEText
+    from email.utils import formatdate
 
     address = extra.get("address") or os.getenv("EMAIL_ADDRESS", "")
     password = os.getenv("EMAIL_PASSWORD", "")
@@ -1092,6 +1093,7 @@ async def _send_email(extra, chat_id, message):
         msg["From"] = address
         msg["To"] = chat_id
         msg["Subject"] = "Hermes Agent"
+        msg["Date"] = formatdate(localtime=True)
 
         server = smtplib.SMTP(smtp_host, smtp_port)
         server.starttls(context=ssl.create_default_context())